he Port of Houston Authority has touted a big increase in steel imports as a result of the shale-driven energy boom gripping Texas and other states.

But the port also has seen an uptick in imports of another energy-related material: wind turbine parts.

Some 55,800 tons of wind equipment sailed from foreign ports to Houston’s in 2011, nearly twice the previous year’s tonnage.

Imports of blades, towers and nacelles – which cover a turbine’s generator and other electrical components – had peaked at 59,680 tons in 2008 but then plunged 40 percent before last year’s surge.

“In 2009, financing stopped. Projects were put up on the shelf,” said Ricky Kunz, vice president of the port authority’s origination division, which develops trade at the port. “Now you’re beginning to see it come back.”

It appears the trend will continue, at least in the immediate future.

Kunz said 160 turbines are scheduled to arrive from China, and five vessels loaded with turbine parts will be coming in during the next few months. He said nations sending wind equipment to the port include China, Brazil, Spain, Denmark and Germany.

At least one other port is also seeing a rise in wind equipment traffic. San Diego’s more than quadrupled from 2010 to 2011, port officials said.

Demand for domestic wind farm projects has spurred the demand for imported parts, even in the face of a significant increase in U.S. manufacturing in the past decade.

According to the Congressional Research Service, 50 percent to 60 percent of the thousands of component parts that make up whole turbines are now being produced in the U.S., up from 25 percent in 2005.

The supply chain, however, remains global.

Made in Texas

“Because turbine blades, towers, and certain other components are large and difficult to transport, manufacturing clusters have developed in certain states, notably Colorado, Iowa and Texas, which offer proximity to the best locations for wind energy production,” the Congressional Research Service said in a report last year. “The U.S. wind turbine manufacturing industry also depends on imports, with the majority coming from European countries, where the technical ability to produce large wind turbines was developed.”

So while Houston’s imports have increased, it is neither counter to – nor indicative of – the national trend, said Peter Kelley, spokesman for the American Wind Energy Association.

“Industrywide, we’re using far more U.S.-made parts,” Kelley said.

“It’s not that these numbers are going to zero, but they are showing a decline, and that does represent the national experience, which is we are importing less and less of our wind turbine parts.”

Tax credit

Kelley noted, however, that the industry fears the explosive growth in domestic manufacturing – along with Texas’ position as the top wind power-producing state – will take a serious hit if Congress fails to extend an expiring federal tax credit intended to encourage wind energy production.

The production tax credit, set to expire at the end of the year, pays wind farm operators 2.2 cents per kilowatt-hour of power they produce for a decade.

Kelley said the incentive has made wind power cheaper, spurring the development of domestic wind projects, as well as manufacturing.